Collapsible pile-driving mandrel



' Malh 2, 1948. E. w. RIEMENSCHNEIDER ETAL' 2,437,043

COLLAPSIBLE PILE DRIVING MANDR'EL- Filed Nov. 2, `1945 3 sheets-sheet 1 March 2, 1943 E. w. mEMENscHNl-:IDER Erm. 2,437,043

` COLLAPSIBLE PILE DRIVING MANDREL Filed Nov. 2, 1945 3' Sheets-Sheet 2 :fr ,1151! [av f4 19 wird,

March 2, 1948. E. w. YR1EMENscl-mEIDER ErAL 2,437,043

COLLAPSIBLE PILE DRIVING MANDREL Filed Nov. 2, 1945 3 Sheets-SheetA 5 l s 11u Patented Mar. 2, 1 948 UNITED Para osi-1 ic e incorporation offOliioi Appucationnevemheria miaseriarnu. 1621x194.H

' regime A(ci. armer The invention relatesgenerally to Kapparatus fon v. driving tubular piles: or shells` intofthea'groundi, and more particularly-to, a. collapsible core vor mandrel Which vlits` Within: andufrictionallyr'e i 1 the-shock of thedrivingfhammer. on the. various tofprovideva novel andimproved collapsible mar-1my gages the shellduring thefgdriving operation;.andi drel which overcomes the disadvantages of prior which is collapsible radially; forwithd-r-zwv-atfrom; the shell after it is driven. Y

Prion collapsible. mandrel'. :constructions have been .-adaptedl.v for driving. tapered tubular piles@ constructions; whichis adapted to. be made in longitudinal sections without' limiting vthe length per section` or of, .the assembled sections; and.rv whichis` inexpensiveto. manufacture, and.v use.v

by frictionalengagements-of radially eXpansible-:ml andhasfa-long life.

steel segments.. with the pilef..shell, ibut. inv order. to obtain suilcient frictionalengagement,` they` shell is required to. have a-.s-ubstantial amounts of. taper. Where relatively long.; piles `arerequired, such amount of taperA becomes imprac 5.`. sub.combinations,- which comprise vthe present@ ticable, becausethe upper.. endof suchipile.- is

necessarilyA of excessively. largev diameter. GJbvi.-h Y

ously, straight or cylindricahtubular piles Acan--` not be driven-With*suchconstructions.because of the lack of suicientfr'ctional engagement.

In .the case of` circ.unri-ferentially,Y corrugated; piles, prior collapsible.. mandrel constructions@ havek hadtheir segments correspondinglycorrugatedto t into each of. the; pilefcorrugations; son

that they drivingimpactl onthe mandrel? is` taken;

by its engagement with -the; corrugations; and. the shellisdriven ,without distortingl or.- damage. ing( the corrugations.:A While such'l constructions-,ffunction satisfactorily with;l corrugated shells.;

' they are-v very` expensiveA to.makevbecausethe:30

mandred segments must be accurately shaped. taf' fit all of. the individual *.corrugations:oytheshellz- Such mandre'ljis adapted-.fon use. with only. one@ size of corrugationsf and -cannotb'e `use'dv-fon drivingplain or smooth piles. 7.., i35

It. is a general. object of: the .present inventions to provide anoveland improvedycollapsible-mam., Y drel which4 is adapted.to..drivestraight .or taperedm tubular. pilesfwhicl'i` may be plain,. ,uted orf cir:-l cumferentially corrugated.

Another object is toprovidea c ollapsfihlennan,V

drel which is, adapted to. lt..a.corrugatedpile for. drivingl the same, vvitlfiout;,requiring-itl'ie.mandrelfv segmentsv to be corrugated.

Another obi ect .iste provide an impr'cvedmam 45 A further object is toprovide animproved man?- drel construction for driving a corrugate.d=,pile5D shell, in whichl uniformefrictional.contactisfinr suredi over the. entire` surface, oiall the .corrugaf tions. Another object is vto provide an. improved. co1.

These .and other objects, which will beapparentstofthose .skilled in the` art from the follow-r ing description are accomplished by theiparts.

construction; arrangements, combinations, and

{"inventiom the nature-foiY which isset forth in.-

the following generalfstatement', and preferred.;

embodiments of whichy areset for-th inthe fol--Y distinctly pointed out and set. forthy in the apr pendedclaims forming parthereof.

In ..general.terms,rthernature, of the invention.: may. be..stated as; including acollapsible pile.4

driving mandrel. ,having a center shaft, a'plu.-`

""*rality of` circumferentially.arranged. segments yorvr leaves-surrounding.- said shaft, `cooperating,means.

on the .shaft-andi segments. for forcing the segments radially outward when :the shaft is driven. e. downwardly, 1vthe -segments having` resilientrub-- movably, connecting the; segments to saidshaft.

forradiall'y collapsing, saidl'segments when; the,V gshaitisvraised.upwardly relative to the .-segments. Y Referring to thedraw-ings forming `part hereof). Figure .1 is..a.1ongit1.1dinal r`sectional view of fac.' collapsible .mandrel/,embodying theinvention and?. shown-.in expanded=position,. said section being;- 40K.takensiibstantially-fonline. I I l, Fig. 5;

Fig..2f.s an. enlarged ..fragmentary sectional ,y view similarltofEig. 1, showing the mandrel expanded..nto engagement with a. corrugated tu-I bularlpile shell; y

tion.;

Fig...4 asimilar view,.showing.the mandrelin= collapsed .position for., withdrawal-from the shelhs.

Eig. .5.is .acrosssectional view.v as on .line-:Eie--tii` uFig.,2 xvithldistantpartsremoved;

Fig... 6 sis.. aI crosspsectionabview as: on l-ineV 596,.,

Fig,V withthe :pile shell removed;

Fig. v.7 Lisa. cross :sectional view ason line ile-1;..`

lapsible vnfiandrel^ for drivinga corrugated. prilewas Fie-'2, with lthe pile shell removed;

shell", in. which eachA corrugation; is. backed-fum,

duringdriving. so as.. to.v prevent .distortion-:tor l' damge-Omthe Sh11`l Y Astill'gfurtherobli ect is tmprovide amimprovei collapsibleemandrel .-.which.-.functionss to3 cushions.i co i" Eig..8 .is across-sectional. view as;` on line -8-8; .y Fig.;J withthe-.ple shell :and bottom-cap-removed; y Fig. 9is,.a. crosssectional view- -as-.on line` 9.-9,

'Uberacingsffor..frictionally` engaging a'pile shell. .1 in.,.expandedt positiom and ,cooperating means Fig. .3 is anew. erinnerte. Fig-s 2 showing they` mandrel-partially. expanded` in 3pre-driving posi?` i Fig. 1(l.is. anjenlarged-iragmentarylongitudinal2,v

sectional View showing one of the joints between longitudinal sections of the mandrel segments.

Similar numerals refer to similar parts throughout the several views of the drawing.

The embodiment of the improved collapsible mandrel shown by way of example in the drawings and described herein is adapted for driving. a tapered tubular pile shell, and is shown as. applied to a tapered tubular shell having circumferential corrugations. It is to be understood that the collapsible mandrel comprising the invention is equally well adapted for driving plainV i tapered tubes or tapered tubes having longitudinal flutes, without departing from the scope of the invention defined in the claims. Likewise, it is to be understood that the collapsible mandrel in a circle concentric with the center shaft. Thus, when the segments I6, I'I and I 8 are fully collapsed Vor closed, as shown in Fig. 9, the cross section of the mandrel is non-circular because the spaces A, B and C have been closed to reduce i the area of the mandrel while preserving the same radius of.curvature of the individual segments.

, The sectional view of Fig. 9, showing the segments in closed position is taken on the same plane as Fig. 6, which showsthe segments fully expanded.

The segments I6, Il and I8 are arcuate in vcross 'section and are`each preferably provided with longitudinal stiifening ribs I6', Il and I8', respectively, located midway between their longiof the present invention can be designed for fit- Y three longitudinal sections joined together as one l unit, the number and length of the longitudinal sections can be varied as desired to produce mandrels of a large variety of lengths, and having various-degrees of taper.

The novel collapsible mandrel preferably inoludes a center longitudinal shaft or core which may be made up of a plurality of tubular sections joined together. As shown, the shaft may consist of tubular sections decreasing progressively in diameter from the relatively large diameter section I Ia at the top to the relatively small diameter tubular section IIe at the bottom of the shaft. The tubular section IIb of the shaft is slightly smaller in diameter than IIa, and may have its upper end telescoped into and suitably secured to the section IIa. In the same manner the relatively smaller section IIc, is securedto section I Ib, the next smaller section I Id is secured to section IIc, and the smallest section IIe is secured to section IId.

The tubular sections IIa, IIb, IIc, IId, and IIe, when secured together, comprise the center shaft ofthe mandrel which decreases in diameter at intervals from top to bottom. The top section IIa has secured on its upper end, as by screws I2, a tubular socket I3 which is part of the base plate I4 of a usual pile driving head. The upper boss I5 of the base plate I4 preferably ts within an adapter which mounts an anvil block above the boss I5 for receiving the blows of the driving hammer and transmitting them through the mandrel. The construction of the driving head per se forms no part of the present invention.

The improved mandrel includes a plurality of circumferentially arranged segments I6, I'I and I8 which are mounted on the center shaft for movement radially thereof. As shown in Figs. 5, 6 and 7, we prefer to have three such segments making a substantially complete circle in cross section. In a tapered mandrel according to the invention to be used for a tapered tube as shown in the drawings, the segments I6, I'I and I8 may be-made by slitting a plain tapered tube having substantially the same degree of taper as the tapered pile shells which are to be driven by the mandrel.

A s shown in Figs. 5, v6 and 7, the segments I6, I'l land I8 are made by taking a longitudinal cut of substantial width at three equally spaced locations A, B and C, 120 apart, and when fully expanded as in Figs. 2 and 6, the segments lie tudinal edges and extending radiallyinward toward the center shaft. The ribs I6', I'I' and I8' taper gradually from top to bottom, so that the space between their inner edges and the shaft sections is substantially constant throughout, as in- 4dicated in Figs. 1,2, 3 and 4.Y These ribs may be 'suitably attached to the inside ofthe circular segments as by welding.

The means for mounting the segments I6, I1 and I8 on the center shaft II, for radial movement relative to said shaft, preferably includes pairs of links I9 pivotally connected at their inner ends at 2U to ears 2I preferably extending radially from a collar 22 secured to the top section IIa of the shaft adjacent the socket I3 of the base plate I4. The outer ends of the links I9 have pivot bolts 23 which extend through inwardly upwardly inclined slots 24 in the stiiening ribs I8', I'I and I8' respectively.

In the fully expanded position of the segments shown in Fig. 2, the links I 9 are substantially horizontal and the pivot bolts 23 engage the outer ends of the slots 24 to fully expand the segments I6, I'I and I8 respectively. In the collapsed position of Fig. 4, raising the center shaft II raises the pivots 20 of the links I9 and causes the pivot 'connecting means may include a collar 26 secured on the bottom end of shaft section II e by means of a bolt 21, said collar having radially projecting ears 28 atV12 0 intervals opposite the ribs I6, I1 and I8. The ears 28 are connected by pairs of links '29 to the respective ribs I6', I'I and I8', the linksl being pivoted at their inner ends to the ears 28, and having pivot bolts 30 at their outer ends passing through vertical slots 3l in the ribs.

As shown in Fig. 2, the links 29 are substantially horizontal when the segments are fully expanded with the pivot bolts 38 at the bottoms of slots 3|, and as shown in Fig. 4, the pivot bolts 30 ride upwardly in the slots 3l when the segments are radially collapsed by raising the center `shaft I le.

Preferably, the top end of each segment is reenforced by a segmental horizontal reenforcing plate 32, the outer edge of which is welded to the upperedge of the segment. Each segmental reenforcing plate 32V supports a segmental carrier plate 33 secured to the reenforcing plate by bolts 34. The carrier plates 33 each have a radially extending hook 35 at their central portions, so that the hooks are spaced 120? apart circumferentially, and the base plate I4 is provided with three'. dependingV loops, pirated* to .ears 3j thereon at 1go?. interfvalsstor Stakflnsfunder the.

hooks 35.'.

Intheexoended nos engitdlev` the hacks, but `titl-,11.0.15 engage under the,- same;;. in,theme-drinne position-1 of Fis- 3, the loops 36 engage under the hooks 35 to support; the. segmentsin partiallxa etlndedposi-ton; and in.V the, collapsed.. position. on Fla., areI spaced.abovey the` hooks 5 Eachof thefSteelsegmn 5;. the. loops 36;I

tenerne. ette-:meeste tentation. themendtel tudinal sections sections being-.lx1 da generally; at.:y 5.4... 55.. and..

5B in.. ne, 1.. 'me-.{jeintsbetneenlthe. longitude; nal sections may@ be made as, shown in Eig.; 1v-0 in which theaadiacentt eodsofthe sesments HV of. longitudinal.; seot1ons-. have. segmental.. joint. plates 51 welded thereto as indicated at, W,. said; Weldsbeine made.;ations` metemos scalloped. sur.h

vided on its outer curitedlirf-aoe-fwha resilient...

rubberv facines.ndioated-4at.f Ilia, lla.l and Isa.

The rubber racines. arie preferable vulcanized.`

a series ef-Y preferabiyjhorlzontal; wedge plates;l

secured at intervals tdthefcenter shaft,` and cooperating with circumferentially arranged' wedges on Ithe inside off th-e fsegme'nts 'The vnumber and' spacing ofl tlleseV wedge 'platenmay be variedj if' desired. Inthedrawings;thefshaft Section Hav has three verticallyspacedj 'Wedge' plates 38, 3,9 and .4.0; the shaft section lil b-has'f two vertically spacedwedge plates. HfandflZf; the shaft section itc has.` twoverticallly. spacedwedge plates '153a and.44 theshattzsectionl Hdihas two-vertically spaced. wedge platesdllfaand 465,. andi shaft section I te has. threefverticallyi spaced Wedge plates 41; Mend. 419...

Each, of these. wedge plantesiengages a: circum.

ferentia-lly arranged `series. of .wedges .which are.

secured .as by `Welding-.01.1. the inner. surfaces of 535 of the carrier plates 3.34.3 In.this..positionthe;

4QF to be placed over the bottom end ofthe mandrel thesegments Ille, Il andi-t8. The.. wedgefplate 38..

engages at its,` Quteredgesa. pairE of. Wedges 50..,on. each. segmentI preferabln spaoec'tat; 1. equal diss,

tances laterally of'the central strengthening ribs Si.rn-iltftrly,V the wedge platesa, .40;.4l3I 42,. 43 and.,

imilarly arrangedat proper;

44K'engagelike-WedgesY d vertical locations. on, thes egmen,ts,..v

EaCllof. the. Wedge. pltesi 3B-,404l.;42, 43V and are provided witnslots .5I extending @die mentsin accordanoe"with together bygbolts. Slifer. joining; they. longitudinal. sectionsV of each segmenttogethelyto. produce a unit o f the required lengifh.

shells P drivenfby thdi-Inprovedjmandrel; may;

be crcumferentiallyl corrugated sheet metal.-

tubes. The pile shells,aretmadeup-pof la plurality of longitudinalsections B- and; Pf, having-their ends telescoped togetheiftandthe upper end of eachlongitudinat pil ectiom being1 preferably plain or nonecorru {ted-as indicated-atti); best shown in Figi 110.-, the.;bottom` end of one.

.corrugated pile. section. R1 ts Withinv thence-- "Lcorrueated portion vlill ofthenlesection l5"below,A

andv engages thetop. oornugaton .Bcl tl'iereof.V

In the. operationf,0...thea iflllloved;V mandreldn driving a pile shell, for e amplela; sectional ein, cumferentially Y corruga. d-shell-.-as;.shown inA the.

drawings thebammer. nddriyzng; bead assembly are.snppnted;ir:l,.usl1tlfld fashions by'. as Gitaneboom and. the. like-anathema .the-loops.. 36: of tnefbase platelpl-under-the h ooks.

entire assembly of` the hammer, driving head and mandrel is movedftol th oca-t ior1.rv off lthe pile.: to-be driven andraisedj-su cientlyil aboveV the` ground level 'toallowtlietpile-setons YP andP'- and movedk upwardly; tltiereonA until. ythe corruga tions frictionally engage; thezrubber faeings ofV the segments. Obviously-,the largestpile section P will be plaoedeover the mandrell=rst, andgthen; followedk by thesuccessivelysmal'ler Sections Pf which have their ends telescopedf--together as inally .inward froml their; outer," edges for, receiving' theribs. f6", Ilv andjfl?. 'As shownin Eig..9,'the

slots Slj` aremadeideep'enough to accornxnodate.` lapsedposition offthe .seg-

the ribsI IlQfull'y. col ments.

The wedge plates 45.21.45,. 41,. 48. and 4.9 are. of

relatively small; arx'ea,A bein`g`located Within. the.

small endo'ffthelnalldlel. and are arranged to have the bottoms of slots 52 engage wedges..

mounteddirectly onthe strengthening ribsy I6',

l 'l' andL [8",1 as .indicated Vinthe yshovv'ing. of Wedge. platedlliin.FigsQZandjQ In .the smell; end; ef tnenendrer the. laterall dimension oftheseginents'lssuohthat the wedge ingl force neednot'be4 distributed t0. the ysegment at laterally spaced points,but can `be vtransmitted directly throughthe strengthenlngfribs. Accorde ingly, as shownjinfFlgs.. Zand 7,'the wedges y53 are blocks securedas by weldngsintorecesses.or slots cutinp'the Vstrengtrluer'1ing.,'ribs ,.IE.' and, I1' and-1,8, andi arewedgeably 'neaged byv the bottom slotsl 52 in the jwedge kplate Fel? @omette-a and 'transl Fig. 10.

In the pre-driving; nositlonof..v the mandrelLtne of the mandrel segments to Wnichthey are attacked, with thev result that bottom .endsofi the segments. IB, IlziandJ tend to swing. radially o outward away, fromthecenter shaftiwhichmove ment islimitede by;` the. bQttQm-..links2.9. Thus, as the pile sectionsv are. raisedfupwardly around the mandrel-, which; ralsingimay be done by a rope and pulley; deylceas-the sections engage. the rubber-V feci-nesv theyl are;` held. in position notonly by such frictional engagement, but by the outward swingingtendeneyaof the mandrel seg-- ments.

After the pile sections are thus applied to the; mandrel, the joints betweernthefpile sectionsmay *besealedgif desire d..wit aplastldmaterial, and a bottom cover or cap. 6; lsfplaced over; the bot,

torn end o f the bottom pile ectiom-withthef man?.y

drei inserted. therein-1, for preventing-the entrance. of dirt and the like immeenterina-the mandret as the. pile shellrisidrlyext.-

The. entire. assemblye includine .tbe.1;,1arernenv is.:

then lowered. into.,p .itio

for. the .pile..- and..;hhaawei;sht .0. the-bammeris;l ordinarily sucient to complete -exmrnsinmoijthey -..ir.lelfwbefmade in. lonse con ement enelthlthreesuolr.

. $90111 weldingplactice.. -Thesegmental joining lates-51 may be:secured As indicated.v Ain llgs-i.V 2,'i 3; 4. andi 10',..- the` pile..

drole. is supported; in. the.- predriving:position 0.1. Figa: SrbyV 'engaging hooks 35 and loopsifsupportlngpthe;same. are. i located radially; outward.;Ottheeerltergravity.v

7 mandrel to the position shown in Fig. 2, although in some cases it may be that themandrel is not fully expanded until the Vfirst blow of the hammer is struck. As shown inFig. 2, the full expansion of the mandrel squeezes the rubber facings into the individual corrugations of the pile shell so as to substantially fill the spaces within the corrugatlons.

Thus, each corrugationV is supported or backed up during the driving operation so as to uniformly distribute and absorb the driving impact of each stroke of the hammer upon the mandrel. As a result, the shell is driven into the ground without distorting or damaging the individual corrugations, and the rubber facings function to cushion the shock of the hammer blows upon all of the parts of the mandrel, thereby greatly prolonging its life.

The rubber facings Ilia, l'la and I8a provide sufficient positive frictional engagement-with the -pile sections to drive a plain or non-'corrugated tube which may have a very slight degree of taper or may even be a straight cylindrical pile shell. Thus, the diameter of the upper'fend of a relatively long pile shell may be kept to a desired minimum, in contrast with the condition where a required amount of taper results in an excessively large pile diameter at the top end. Moreover, the rubber facings on the improved mandrel provide for fitting the mandrel into a pile shell having circumferential corrugations of various sizes, because it is not necessary to provide pre-formed corrugations on the outside of the mandrel segments for fitting the corrugations of the pile shell, as is the case with a mandrel having metal facings on its segments.

The improved collapsible mandrel may be made in longitudinal sections of any length, and may have any desired assembled length which may be required by the particular conditions during the driving operation, and the improved co1- lapsible mandrel is inexpensive to manufacture and maintain, and easy to operate.

After a pile shell has been driven to the desired depth by the improved mandrel, as previously described, the driving head is closer to because such words are utilized for Vdescriptive purposes and are intended to be broadly construed.

Moreover, the embodiments of the improved construction shown and described herein are the ground than at any other time, and the lifting loops 3S are therefore ordinarily accessible to a man standing on the ground, although in unusual cases he may be required to climb to an elevation where he can reach the loops. In

either case, the loops are swung outwardly free of the hooks 35 and the hammer and driving head assembly raised to a position such as shown in Fig. 4, by attaching a cable or the like to the ears 62 provided at diametrically opposite locations on the base plate i4 of the driving head. As the center shaft of the mandrel is thus raised, the segments thereof will first be forced inwardly by the resilient action of the rubber facings, and then the links i9 and 29 will draw the segments into fully collapsed position, whereupon the entire mandrel may be withdrawn from the -pile shell.

As soon as the end of the mandrel clears the top of the driven pile shell, the crane boom is moved slightly to one side and the end of the mandrel set on the ground, so that by lowering the driving head assembly a few inches, the lifting loops 36 will slide over the hooks 35 and drop into the pre-driving position of Fig. 3; Raising the entire assembly will now lift the mandrel in the pre-driving position of Fig.V 3 in readiness for driving another pile shell -in-the manner previously described.

by Way of example. and the scope of the present invention is not limited to the exact details of construction of the various parts.

-Having' now described the features of the invention, the construction, operation and use of a preferred embodiment thereof, and the new and useful advantageous. resultsv obtained thereby; the novel and improved constructions and arrangements, and reasonable mechanical equivalents thereof which are obvious to those skilled fin the art, are set forth in the appended claims.

1. In combination. a corrugated pile shell, a mandrel for driving said shell into the ground by engaging the inner surface of the shell, said Vmandrel including a plurality of circumferentially arranged segments having soft rubber facings, and meansV for forcing said segments radially outward to squeeze said facings into the corrugations, said facings having sufficient radial thickness to substantially fill said corrugations when the segments are forced radially outward.

2. In combination, a corrugated pile shell, a mandrel for driving said shell into the ground by engagement with the inner surface of the shell, a driving head on the upper end of the mandrel, said mandrel includingV a, plurality of circumferentially arranged segments having soft rubber facings, means for forcing the segments radially outward to squeeze said facings into the corrugations to substantially fill the corrugations, and means on the driving head for supporting the segments in partially expanded predriving position with said facings engaging only the inner surfaces of the shell between corrugations.

3. In combination, a corrugated pile shell, a mandrel for driving said shell into the ground by engagement with the vinner surface of theshell, a driving head on the upper end of the mandrel. said mandrel including a plurality of circumferentially arranged segments having soft rubber facings, means for forcing the segments radially outward to squeezesaid facings into the corrugations to substantially ll the corrugations, and means on the driving head located radially outward ofthe center of gravity of each segment for supporting the segments in partially expanded pre-driving position with said facings engaging only the inner surfaces of the shell between corrugations. Y

fl. In combination, a corrugated pile shell, a mandrel for driving said shell into the ground by engagement with the inner surface of the shell, a v

vdriving head on the upper end of the mandrel, said mandrel including a central shaft and a plurality of circumferentially arranged segments mounted 0n the shaft and having soft rubber- 9 l0 means for movl1 1g the segments radially inward UNITED STATES PATENTS as the shaft is ralsed.

EDMUND W. RIEMENSCHNEIDER. Number Name Date DOUGLAS T. GRETH, 757,767 P001 Apr. 19, 1904 5 1,140,303 Feder May 18, 1915 REFERENCES CITED 1,865,653 Upson July 5, 1932 The following references are of record in the le of this patent: 

